A central vacuum system comprises a vacuum motor and dust collecting waste receptacle, located in a remote area of a fixed dwelling, such as a garage or basement. Central vacuum systems may also be installed in mobile homes and recreational vehicles. A series of connected plastic pipes are provided throughout a building, which are connected to a plenum associated with a central vacuum motor. A series of normally closed but openable inlet valve assemblies are provided on the ends of the pipes into which a hose cuff of a flexible vacuum hose may be inserted when the inlet valve assemblies are open. The hose is portable and hand held. A hand held rigid suction wand is typically located at the free end of the vacuum hose with an appropriate dust and debris collecting nozzle. Some nozzles are electronically powered for cleaning carpets or the like and are called power head nozzles.
Typically the plastic vacuum pipes are located within the walls of a building out of sight, and a low voltage wire is strung along the pipe from the vacuum inlet valve assembly to the vacuum motor. A conductive material, such as a conductive metal ring is positioned in the insertable hose cuff located on the flexible vacuum hose. The metal ring closes a contact in a low voltage circuit which in turn activates the vacuum motor, creating suction in the pipes and in the connected vacuum hose. In this way, in some older designs, suction is automatically provided upon the hose cuff being inserted into the inlet valve assembly, or when the flexible hand held hose is connected to the in wall rigid vacuum piping system. Passing the free end nozzle of the sucking wand over loose debris will cause the debris to be sucked up into the wand, through the flexible hose, through the valve into the vacuum pipe and eventually to the dust or debris collection plenum located adjacent to the vacuum motor at the remote location such as a garage or basement.
In some cases, a higher voltage or normal household power circuit is included as part of the wiring of inlet valve assembly, typically in the form of a female electrical socket. A corresponding male connector associated with the hose cuff on the vacuum hose connects the 120 volt circuit to a power nozzle or beater bar mounted to the free end of the hand held wand for agitative cleaning of carpets or the like. The electrical connection is made upon the insertion of the hose cuff into the inlet valve assembly. A switch can be provided in the handle of the wand for turning the beater bar on or off. In most more recent designs an off/off switch can also be provided in the hand held wand or associated handle for controlled operation of the central vacuum motor. Examples of some prior art devices are disclosed in the following patents: U.S. Pat. Nos. 3,036,814, 5,111,841, 5,886,299, and 5,349,146.
Central vacuum systems are gaining in popularity for a number of reasons including: the noisy vacuum motor is located in a remote location (garage or basement) and the sound is less intense beside the user. The flexible hose is lighter to move around than a heavy vacuum motor and the only air disturbance within the dwelling is suction—there is no exhaust blowing from the vacuum unit in the room being cleaned which launches as yet un-vacuumed dust and debris into the air. For these and other reasons, central vacuum cleaner systems have been growing in popularity, both in new construction and as a retrofit installation for existing dwellings.
However, problems exist with the prior art inlet valve assembly designs. One of these problems relates to the hinged door that is used to cover the vacuum inlet when it is not in use. Often the door hinges along a top or bottom edge and is spring loaded to a normally closed position. When the door is open and the hose cuff inserted, the free edge of the door rests upon the flexible hose. As the hose is pushed and pulled across the floor to remove debris, the hose flexes which in turn flexes the door resting on the hose. Violent movement of the hose, such as flicking the hose to free it from some obstacle during vacuuming, can create large stresses in the door, causing damage. Damage to the door can lead to a loss of suction at that inlet valve assembly rendering the whole system useless until the door can be resealed. The pushing and pulling of the hose across the floor also causes the hose to rub against an edge of the door which wears a hole in the hose over time which again causes a loss of suction. What is needed is a way to reduce the potential damage to the door and the vacuum hose arising from the door resting on the vacuum hose.
Another problem arises from the use of metal components, for example for the attachment or mounting flanges. While such metal mounting flanges are highly functional, metal is expensive to use. Further the attachment flanges are typically mounted over mounting posts in a left hand or right hand manner, requiring the installer to keep on hand supplies of both left and right hand versions to satisfy the requirements for any given job. What is required is a design for lower cost component that is also more universal in application.
Another problem arises when seeking to use the mounting flanges for a retrofit installation. In new construction the mounting flange is nailed to a convenient stud and then the wall board is installed over the mounting flange. In a retrofit installation the hole in the wall board is typically too small to accommodate a mounting flange, meaning that the presence of a mounting flange leads to the requirement of a big enough hole in the existing wallboard to reveal the stud. This requires making significant repair to the opening after the mounting flange is installed and adds to the time and expense of a retrofit installation. What is desired is an inlet valve assembly that lends itself to easy and efficient use in a retrofit installation with a smaller hole in the wall to avoid excess repair.